Inventory-Aware Cross-Section Sizing for the Simultaneous Minimization of Structural Mass and Fabrication Cutting Waste in Steel Structures

In steel construction, the material consumed comprises the mass built into the structure and the off-cuts left when members are cut to length. Sizing procedures minimize the first and disregard the second, assuming that the lightest structure also needs the least steel. This paper shows that the assumption can fail. An automated procedure is presented that drives an existing finite-element model through a programmatic interface, performs ultimate-limit-state member checks at every step, and evaluates the cutting of every configuration with a best-fit-decreasing heuristic on a shared inventory. Three material sources are covered: mill bars, a finite inventory, and a hybrid. The search returns the minimum-mass design and the minimum of a weighted objective that adds cutting waste to built-in mass. Exhaustive enumeration on two reference structures verified the search; an exact cutting check on the frame showed that the heuristic leaves the mass optimum unchanged but can alter the weighted optimum. On three benchmarks, a heavier but better-cuttable alternative used less steel than the statically lightest design by up to 1553 kg (9.2%). On a large hall, the hybrid mode lowered the built-in mass of the weighted inventory-only optimum by 4.4 t and raised governing utilization from 53% to 91%.